1. Field of the Invention
The invention relates to polishing abrasives and polishing tools. More particularly, the invention relates to methods and apparatus for the abrasive polishing of vehicle windshields to remove scratches and/or stains.
2. State of the Art
Automobile, truck, and other vehicle windshields are subject to scratching by abrasive dirt, sand, and small stones. This is particularly so in certain environments rich in sand and other abrasive materials. Scratches on vehicle windshields are not merely an aesthetic problem, but can become a safety problem when the interfere with the driver's vision. The problem of scratched windshields is most prevalent in commercial and military vehicles which are frequently subjected to harsh environments.
The presently known method for removing scratches from vehicle windshields is to use a rotating polishing wheel such as the electric polishing wheel 10 shown in prior art FIG. 1. The polishing wheel 10 includes an electric motor 12 and a polishing pad 14 which is rotated by the motor 12. The motor 12 is typically driven by an AC voltage and is provided with a standard power cord 16. The polishing wheel 10 is usually used in conjunction with a polishing abrasive 18 such as a rare earth cerium oxide mixed with water. The abrasive may be applied to the windshield 20, to the pad 14, or to both. The polishing wheel 10 is powered on and the pad 14 is moved over the windshield 20 with the abrasive 18 being moved between the pad 14 and the windshield 20. Pressure is applied to the pad in order to effect an abrasive polishing. While this method is somewhat effective, it has several disadvantages. First, the polishing pad 14 is typically much smaller than the windshield 20 and therefore the windshield 20 must be polished in small segments. This results in an uneven polishing which can distort the glass (or other windshield material) and result in a distorted view through the windshield. Second, the rotating polishing pad tends to spew the polishing abrasive all over the vehicle, the operator of the polishing wheel, and the immediate surroundings. This requires a substantial clean-up effort after the polishing is completed. Third, the polishing wheel usually requires an AC power supply. This limits the availability of an emergency windshield polishing in the field.
Yet another problem is trying to remove spots that result immediately after the sweep of the windshield wiper over a wetted glass surface that truely cause restricted vision to the vehicle driver particularly when driving the vehicle in the rain. Even with the use of the windshield washer fluid, this condition of spots is not corrected simply because these spots are, in fact, stains on the outside glass surface. These stains are the chemical residue of, for example, road salt, oil, transmission fluid, carbon, acid rain, etc.
So far as is known, there is no presently available easy and facile method and apparatus that can be used by both the automotive technician and/or the laymen to deal with this long standing problem of scratch and/or stain impairment of windshield visibility which interferes with safe operation of a motor vehicle.